Adapter for sewing machine attachment



1967 R. w. BURGESS ETAL 3,302,601

ADAPTER FOR SEWING MACHINE ATTACHMENT Filed Feb. 5, 1964 INVENTO'R RM wfB ATTORNEYS United States Patent 3,302,601 ADAPTER FOR SEWING MACHINE ATTACHI'VIENT Robert W. Burgess, Orange, and Edward J. l Vanat, New

Haven, Conn., assignors to Mite Corporation, New

Haven, 01:111., a corporation of Delaware Filed Feb. 5, 1964, Ser. No. 342,625 4 Claims. (Cl. 112257) This invention relates generally to means for mounting a sewing machine'attachment to the presser bar of a sewing machine and is more particularly related to an improved adapter for sewing machine attachments.

The normal sewing machine, whether of the home or industrial type, is supplied with a presser foot attached to the presser bar by means of a screw having a knurled head. A presser foot, as is well known, overlies the material to be sewn and cooperates with the feeding mechanism to apply sutficient pressure to the material to cause it to be fed through the machine past the needle. The needle, mounted on the needle bar, passes through an opening in the presser foot. The basic presser foot is normally used for straight sewing. As is known in the art, a number of other devices falling into the presser foot category are available for most sewing machines, each device having a particular function. For example, there is a presser foot having an elongated slot for zigzag machines, there is a presser foot for holding buttons during the sewing operation, there is a presser foot for sewing zippers, etc.

For more complex operations, a large variety of attachments have been developed. These attachments are adapted to replace the presser foot to perform operations such as buttonholing, milling, blind stitching, faggoting, decorative stitching, and the like.

Such aforementioned attachments are provided with adapters similar to those found on the presser foot for mounting the attachment to the presser bar. They usually require that the connecting screw be fully or partially on screwed and the presser foot removed so that the attachment may be secured to the presser bar by tightening of the screw in a threaded hole in the presser bar. Manipulation of the screw is quite often a diflicult and delicate operation.

Accordingly, it is an object of this invention to provide an improved adapter for a sewing machine attachment which can be readily attached to and disconnected from the sewing machine presser bar.

Another object of the invention is to provide an improved adapter for a sewing machine attachment capable of quickly and securely locking the attachment to a sewing machine presser *bar.

Still another object of the invention is to provide an improved adapter for a sewing machine attachment utilizing a lever which can be readily rotated to lock the attachment to the sewing machine presser bar.

A still further object of the invention is to provide an improved adapter for a sewing machine attachment capable of securely attaching the attachment to the presser bar of existing sewing machines without regard to the variation in thicknes of presser bars between various machines.

Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

Generally speaking, in accordance with the invention, an adapter mounting bracket is provided with an elon- Patented Feb. 7, 1967 gated groove which receives the lower portion of the presser bar with a pin extending into the groove from the bottom thereof for insertion in the threaded hole in the presser bar. A spring-loaded cam plate is adapted to be rotated, by means of a lever, to lock the presser bar in the groove in the mounting bracket.

The invention accordingly comprises the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawing, in which:

FIG. 1 is a side elevational view of an adapter for a sewing machine attachment constructed in accordance with the invention, with the locking lever being shown in the locked position in full lines, and in the unlocked position in phantom, a presser bar also being shown in phantom;

FIG. 2 is a plan view of the adapter of FIG. 1, the locking mechanism being shown in full lines in its dismounted position and being shown in phantom when locked to a presser bar;

FIG. 3 is a partial sectional view taken along the stepped line 3-3 of FIG. 2; and

FIG. 4 is a perspective view of the lower end portion of a typical presser bar.

Referring now to the drawing, a sewing machine attachment, indicated generally at 10, carries an adapter indicated generally at 11, which is secured thereto by suitable means such as rivets 12.

Adapter 11 includes a mounting bracket 13 provided with an elongated groove 14 adapted to receive the lower end portion of the presser bar. Referring especially to FIG. 4, a presser bar 15 is usually in the shape of a cylindrical rod with the lower end milled flat on three sides to give the lower end a cross-sectional configuration roughly approximating a rectangle or trapezoid as indicated at 16. Each sewing machine manufacturer usually standardizes the shape and dimensions of the lower end of its presser bar, and the elongated groove 14 in mounting bracket 13 is designed to accommodate a particular manufacturers presser bars. The presser bar is also normally provided with a hole 17 extending transversely through the lower end portion thereof, the hole being threaded to receive the screw which secures a presser foot to the presser bar.

A pin 18, the diameter of which is substantially the same as the inside diameter of the hole in the presser bar, is secured to the mounting bracket within elongated groove 14 and extends into the groove from the bottom thereof. Pin 18 may be secured to mounting bracket 13 in any suitable manner, such as by means of a press fit, by threaded engagement as shown in FIG. 2, by brazing, or the like.

A bore 21 extends through mounting bracket 13 with its axis parallel to but spaced from the longitudinal axis of pin 18. Rotatably mounted in bore 21 is a shaft 22 having a cam plate 23 secured at one end thereof to rotate therewith. As viewed in FIG. 1, cam plate 23 has a substantially rectangular configuration, and shaft 22 is eccentrically mounted thereto so that in the locked position (shown in full lines in FIG. 1), a portion of the cam plate overlies elongated groove 14. When shaft 22 is rotated to the open position, as will be hereafter explained, cam plate 23 will completely uncover elongated groove 14. The open or unlocked position of cam plate 23 is shown in phantom in FIG. 1.

Shaft 22 extends through bore 21 and terminates in a portion of reduced diameter 24 as best seen in FIGS. 2 and 3, the transitional plane defining a shoulder 25 which, in the assembled position of the elements, is spaced from mounting bracket 13. The shaft portion 24 of reduced diameter is also provided with a flat 26 extending along its entire length. A locking lever 27 is provided, at one end thereof, with an aperture 28, the configuration of which mates with the cross-sectional configuration of the portion of the shaft with the fiat thereon. As best shown in FIG. 3, locking lever 27 is mounted on the portion 24 of shaft 22 and is held thereon against shoulder 25 by means of a nut 29 threaded on the reduced portion of the shaft. Encircling shaft 22 and extending between mounting bracket 13 and locking lever 27 is a compression spring 31 which urges the locking lever away from the mounting bracket. With the locking lever secured to the shaft, spring 31 causes cam plate 23 to be urged toward the bottom of elongated groove 14. The cooperation of the shaft with the locking lever prevents relative angular motion between the locking lever and the shaft. The other end of locking lever 27 is provided with a thumb plate 32 which may be grasped to manually rotate the lever.

The edge of cam plate 23 which faces elongated groove 14 is provided with a beveled surface 33 for providing a camming action, to be subsequently described. If locking lever 27 is rotated to the locked (full line) position as shown in FIG. 1 when the adapter is not connected to a presser bar, the cam plate and locking lever will take up the full line position as indicated in FIG. 2.

The operation of the adapter may now be described. As viewed in FIG. 1, locking lever 27 is rotated in a clockwise direction to the position indicated in phantom. This rotates the cam plate, through shaft 22, to the phantom position thereby unblocking elongated groove 14. The sewing machine attachment may now be attached to the presser bar. The adapter is positioned so that the elongated groove 14 receives the lower end portion 16 of the presser bar 'with pin 18 extending into hole 17 to thereby locate and support the attachment with relation to the sewing machine. Thumb plate 32 is gripped and the locking lever is rotated in a counterclockwise (FIG. 1) direction thereby rotating cam plate 23 in a counterclockwise direction. As the presser bar 15 extends laterally outside of elongated groove 14 as shown in FIG. 2, the presser bar tends to block cam plate 23. Beveled surface 33 on the cam plate engages the protruding rounded surface of the presser bar thereby urging the cam plate away from mounting bracket 13. Against the influence of spring 31, shaft 22 slides longitudinally in bore 21, thereby further compressing spring 31. In the fully locked position, the cam plate and locking lever assume the phantom position shown in FIG. 2 and spring 31 acting between the mounting bracket and the locking lever causes the cam plate to resiliently hold the presser bar in groove 14. When it is desired to dismount the attachment, it is only necessary to again rotate locking lever 27 so that cam plate 23 clears groove 14. In that position of the cam plate, the attachment may be removed from the presser bar.

Thus, the attachment may be simply and readily connected and disconnected to a sewing machine presser bar without requiring the use of screws, screw drivers, and the like. When in place, the mechanical advantage derived through locking lever 27 assures that the attachment is rigidly secured to the machine. Additionally, the spring insures positive engagement of the cam plate with the presser bar regardless of slight variations in size between presser bars.

It will thus be seen that the objects set forth above, among those made apparent from the preceding descri tion, are efficiently attained and, since certain changes may be made in the above construction without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as amatter of language, might be said to fall therebetween.

What is claimed is:

1. An adapter for detachably mounting a sewing machine attachment on the presser bar of a sewing machine, said adapter comprising a bracket, an elongated groove formed in said bracket along one side thereof dimensioned to receive the aforesaid presser bar of a sewing machine with which the adapter is intended to be used, the depth of said groove having a dimension adapted to be less than the thickness of that portion of the aforesaid presser bar which is to be received in the groove, a short stub pin secured in and projecting from the bottom of the groove in said bracket and adapted to be received in a transverse hole in the presser bar for positioning the bracket on the presser bar, lever-operated cam means pivoted to said bracket on an axis offset from said groove and movable to a position covering said groove and bearing against the exposed side of the presser bar to lock the presser bar within the groove, and means for permanently securing said bracket to the sewing machine attachment.

2. The structure defined in claim 1 wherein said cam means comprises a shaft rotatably and axially movable in said bracket, a cam plate secured to said shaft and adapted selectively to either overlie or to uncover said groove on rotation of said shaft, a lever secured to said shaft to rotate the same, and resilient means acting on said shaft for urging said cam plate toward the bottom of said groove.

3. An adapter for detachably mounting a sewing machine attachment on the presser bar of a sewing machine, said adapter comprising a bracket, an elongated opensided groove formed in said bracket along one side thereof dimensioned to receive the aforesaid presser bar of a sewing machine with which the adapter is intended to be used, the depth of said groove having a dimension adapted to be less than the thickness of that portion of the aforesaid presser bar which is to be received in the groove, a support pin secured to said bracket within said groove and adapted to be received in a hole in the presser bar, said support pin extending outwardly from the bottom of said groove, a shaft rotatably and axially movable in said bracket, a cam plate secured to said shaft and adapted selectively to either overlie or to uncover said groove on rotation of said shaft, a lever fixed to said shaft for rotating said shaft, resilient means cooperating with said shaft and cam plate and engaging said bracket for resiliently urging said cam plate toward the bottom of said groove, the edge of said cam plate facing said groove being bevelled to permit sliding engagement of said cam plate over the presser bar to lock the presser bar in the groove.

4. An adapter for detachably mounting a sewing machine attachment on the upright presser bar of a sewing machine, said adapter comprising a bracket, an elongated upright groove formed in said bracket adapted to receive the presser bar of a sewing machine with which the adapter is intended to be used, said groove being trapezoidal in cross-section and opening into said bracket from one side thereof, the depth of said groove having a dimension adapted to be less than the thickness of that portion of the aforesaid presser bar which is to be received in the groove, a support pin secured to said bracket within said groove and adapted to be received in a hole in the presser bar, said support pin extending horizontally from said bracket and transversely to the upright axis of said groove and outwardly from the bottom thereof and serving to fix the height of the adapter on the presser bar, a shaft rotatably and axially movable in said bracket, said shaft extending horizontally through said bracket 12.11 a point offset from said groove, a cam plate secured to one end of said shaft at one side of said bracket, said cam plate being adapted to swing in a plane parallel to said one side of said bracket and selectively to either overlie or to uncover said groove on rotation of said shaft, a lever fixed to the other end of said shaft for rotating said shaft, said lever being spaced from said opposite side of said bracket, a compression coil spring encircling said shaft and extending between said lever and said other side of said bracket for resiliently urging said cam plate toward the bottom of said groove, and means for perrnanently securing said bracket to the sewing machine attachment.

References Cited by the Examiner UNITED STATES PATENTS PATRICK D. LAWSON, Primary Examiner.

G. H. KRIZMANICH, Assistant Examiner. 

1. AN ADAPTER FOR DETACHABLY MOUNTING A SEWING MACHINE ATTACHMENT ON THE PRESSER BAR OF A SEWING MACHINE, SAID ADAPTER COMPRISING A BRACKET, AN ELONGATED GROOVE FORMED IN SAID BRACKET ALONG ONE SIDE THEREOF DIMENSIONED TO RECEIVE THE AFORESAID PRESSER BAR OF A SEWING MACHINE WITH WHICH THE ADAPTER IS INTENDED TO BE USED, THE DEPTH OF SAID GROOVE HAVING A DIMENSION ADAPTED TO BE LESS THAN THE THICKNESS OF THAT PORTION OF THE AFORESAID PRESSER BAR WHICH IS TO BE RECEIVED IN THE GROOVE, A SHORT STUB PIN SECURED IN AND PROJECTING FROM THE BOTTOM OF THE GROOVE IN SAID BRACKET AND ADAPTED TO BE RECEIVED IN A TRANSVERSE HOLE IN THE PRESSER BAR FOR POSITIONING THE 